Carton box

ABSTRACT

A carton box is erected from a blank to form a tubular box having rectangular cross-section and end flaps at one end forming extensions of the front panel, rear panel and side panels of the box. The end flaps of the front panel are divided by a transverse slit into a lower portion and an upper portion, said upper portion being folded inwardly into the box to form a support flap which in a position at right angles to the front panel forms a support to be glued together with the end flaps of the side panels and the front panel when they are folded to their closed position, said lower portion forming a closing flap folded over the rear end flap when in closed position to seal the end closure of the box.

United States Patent 1191 Persson i 1 CARTON BOX Karl Rune Persson, Halmstad, Sweden [73] Assignee: Sprinter Pack AB, Halmstad,

Sweden 221 Filed: Apr. 1, 1974 211 Appl. No.1 456,848

[75] Inventor:

[4 1 July 1, 1975 3,101,883 8/l963 Gimple 229/51 SC 3,581,973 6/1971 Turpin i 229/37 E 3,581,977 6/1971 Kinsky 229/37 R Primary Examiner-Davis. T. Moorhead Attorney, Agent, or Firm0strolenk, Faber, Gerb & Soffen [57] ABSTRACT A carton box is erected from a blank to form a tubular box having rectangular cross-section and end flaps at one end forming extensions of the front panel, rear panel and side panels of the box. The end flaps of the front panel are divided by a transverse slit into a lower portion and an upper portion, said upper portion being folded inwardly into the box to form a support flap which in a position at right angles to the front panel forms a support to be glued together with the end flaps of the side panels and the front panel when they are folded to their closed position, said lower portion forming a closing flap folded over the rear end flap when in closed position to seal the end closure of the box.

4 Claims, 8 Drawing Figures 1 CARTON BOX The present invention relates to a carton box of the kind set forth in the preamble to the accompanying claim 1. Such boxes can be raised from a flat folded condition into a tube having a quadratic or rectangular cross-section, the tube being provided at its ends with end flaps forming extensions of the front panel, rear panel and side panels of the box. These end flaps are folded in at the bottom end of the box for enclosing and sealing the bottom. The box is thereafter filled with its contents, which can be an object, a viscous mass, granular or powdery material. After the box is filled, the filling end is closed by folding in and sealing the end flaps at this end. Sealing can be done by the application of thermosealing coatings on the flaps, or glue beads of known type.

The object of the invention is to provide a box which can be closed at the ends using simple machine aids.

At the same time, the invention relates to the provision of an end closure which solely by sealing the end flaps creates such a tight closure that it can be accepted in most cases, when the box is to contain powdery material for example, contrary to certain known boxes which require a special lining which, on closure of the box, is closed into a hermetically tight envelope, but causes increased costs in manufacture and closure of the box, since expensive special machines become necessary.

These and other desires are met by a box which, according to the invention, has the characterizing features given in the accompanying claims.

A suitable embodiment of the box according to the invention is shown as an example on the attached drawmgs.

FIG. 1 shows the blank seen towards its inside, which is to form the inside of the box,

FIG. 2 is a broken view showing the supporting flap folded in towards the inside of the blank,

FIG. 3 shows the box in a folded condition after securing the side edge flap by glueing,

FIG. 4 is a diagrammatic perspective view of the upper end of the box, after erecting the box, the opening flap being folded outwards, to show the supporting flap more clearly,

FIG. 5 shows how the end flaps are, when nearly at their downwardly turned position, and the supporting flap is folded substantially at right angles to an adjacent side of the box to form a support for the final glueing together of the parts at this end of the box,

FIG. 6 is a sectional view of FIG. 5 looking in the direction of arrows 66 when the box end is completely closed with the opening flap folded inwards and glued fast, the Figure showing the end closure as seen from inside the box,

FIG. 7 shows the other end of the box in an intermediate position during the formation of the box into the position shown in FIG. 4, and

FIG. 8 shows this box end after sealing the end flaps, the wide front end flap being partially broken, to show underlying flaps more clearly.

The blank in FIG. 1 is divided with the help of folding lines into areas which in the box correspond to rear panel 10, front panel I] and two side panels 12,13 hingeable relative to each other along folding lines 14,15,16. Rear panel 10 is extended with a side edge flap l7, hingeable along a folding line 18. On end panel 13 two glue beads 19,20 are indicated, for glueing fast the side edge flap 17 on the inside of side panel 13.

All side panels and edge flap 17 are extended with end flaps at both ends, said end flaps at the upper end of the blank being designated in FIG. I with 17a, 10a, 12a, I la, 13a and are foldable along folding lines 21,22,23,24,25, lying substantially in line with each other. At the lower end of the blank in FIG. I the end flaps are designated by 17b, 10b, l2b, llb, l3b, and are foldable along folding lines 27,28,29,30,3l, lying substantially in line with each other.

At the upper end of the blank in FIG. 1, the end panel flaps 12a and 13a are provided with 45 folding lines 32 and 33. The end flap 11a is foldable relative to end flaps 17a and 130 along side edge folding lines 15a and 16a. When end flaps 12a and 13a in FIG. 4 are folded inwards by folding these flaps along folding lines 32,33, the end flap 11a will be forcibly and simultaneously folded down in a known manner.

End flap 17a has a length from folding line 21 which is less than half of the corresponding length of the other end flaps. End flap 17a is foldably attached to end flap 10a along a side edge hinge 18a. At its opposite side, end flap 10a is hingeably attached with end flap along a side edge hinge 14a corresponding to side end hinge 18a.

A slit 34 is made in end flap 10a, said slit consisting of a straight upper portion 35 and two slantingly directed side portions 36,37 each leading to respective short end portions 38,39, situated in the extensions of side edge hinges 18a, l4a. An opening flap 40 is hereby made available, which is foldable along end edge folding line 22 and is easily bendable by folding along folding lines 41,42.

At the same height as the edge ends of end flap 170, two intermediate folding lines 43,44 extend in line with each other on either side of the portions 36,37 of the slit 34, bounding a substantially triangular side end area 46a between edge hinge 18a and 14a and the slit portion 36 and 37 respectively. From the end of the intermediate folding line 44 and out to the edge of the blank, end flap 10a is separated from end flap 12a by a slit 45. End flap 10a hereby obtains a flap end portion 46, wider than the distance between end edge folding line 20 and intermediate folding lines 43,44. This flap end portion is intended to be folded in over the inside of the blank, and glued fast to it by a glueing flap 47. The glueing flap is foldable along a folding line 48, the distance of which to the intermediate folding lines 43,44 is substantially the same as the distance between these folding lines 43,44 and the folding line 22, which means that the glueing flap 47, after folding down flap end portion 46 will lie below folding line 22 and that folding line 48 will substantially coincide with folding line 22. A glue bead 49 is intended to be applied to the glueing flap for glueing it fast.

The appearance of the blank at side panels 10,12 after folding in flap end portion 46 and glueing fast glue flap 47, may be seen from FIG. 2.

Two 45 folding lines 50,51 extend from the ends of folding line 48 and meet the inner end of adjacent intermediate folding lines 43 and 44 respectively. Two triangular side areas 46b are hereby obtained, which after folding flap end portion 46 inwards will lie against adjacent substantially triangular side end areas 460, each lying between side edge hinge 14a and 18a respectively, intermediate folding line 44 and 43 respectively,

and slit portion 37 and 36 respectively. The object of this arrangement of folding lines is set forth below.

The next operation is to fold the blank together and glue fast side edge flap l7 and suitably also its end flaps 17a, 17b against side panel 13 and end portions 13a, 13b whereupon the flat folded box shown in FIG. 3 is obtained, the ends of the box being open. The box is delivered to the user in this flat folded state.

When the box is set up, the upper end of the box will assume the shape shown in FIG. 4, although here the opening flap 40 is shown folded outwards, to show certain details more clearly.

As may be seen from FIG. 4 a supporting flap 52 is obtained. standing straight upwards before folding down end flaps 17a, I la, 13a. This supporting flap is formed by the double-bent end flap 10a and is automatically folded into the position shown in FIG. 5 when the end flaps are folded down as shown in FIG. 5. In this position the supporting flap 52 will lie substantially at right angles to side panel at folding line 22, thereby forming a stable counter to the pressure applied on end portion 11a when the opening flap 40 has been folded in over this end flap from the position shown in FIG. 5, glueing fast to seal the end closure.

When end flaps 11a, l7a, 13a are folded in and downwards, the supporting flap 52 is forced to be folded in, because end flaps 17a and 13a fold down side edge hinges 18a and 14a so that a double folding of the end portions of supporting flap 52 along folding lines 50 and 51 is thereby obtained. The corners of the box will be extremely well sealed here, and this sealing will be further improved by the opening flap 40 being folded over and sealed. [f extra secure sealing is desired, an extra glue bead can be laid on opening flap 40 at its connection to supporting flap 52, and this glue bead can be comparatively heavy without risk of glue forcing its way into the box and afiecting its contents.

Through the end closure described above, the box can be supplied ready for setting up, whereat closure can take place by quite simply providing the opening flap 40 with a glue bead, or utilizing a thermomelt coating. in spite of the simplicity, such a well-sealed end closure is obtained that no special lining or bags are necessary to obtain satisfactory sealing if the box is filled with powdery material for example.

if so desired, the end closure at the upper end of the box can also be used at the lower end of the box, but in the example shown, the lower end closure is done in another way.

ln FIG. 1 the blank is shown as seen towards its inside. End flaps 12b and 13b are somewhat differently shaped, but both have a triangular corner portion 53 and 54, respectively, foldable along a 45 folding line 55 and 56 respectively.

As is indicated by dotted circles, both the corner portions 53,54 on the outside of the blank are each provided with a glue spot 57 and 58, or can be provided with such a glue spot. On folding the blank for glueing fast the side edge flap 17 onto side panel 13, as described above, the comer portions 53 and 54 are folded in so that comer portions 53 will be glued fast against the inside of flap 10b, and comer portions 54 will be glued fast against flap 1111. The outer edges of the corner portions are designated by 530 and 54a respectively, and in FIG. 3 may be found in their folded-in positions.

End flap 10b has its one end edge 10d slantingly cut in a 45 angle to suite folding line 55 on glueing together. The opposing end edge 10c is drawn in slightly in relation to the extension of side edge folding line 18 in FIG. 1. The one side edge of the end flap is further shaped with a small ear 12c for obtaining good scaling in the completed end closure. One tab 13d of the end flap 13b is slantingly cut off to suit the recess obtained by end edge 10c being slightly drawn in, as was mentioned above.

When the box is set up, its lower end will automatically be closed by the end flaps 12b and 1017 being hingeably connected with the hinge formed by folding line 55, and because the end flaps 13b and 11b are hingeably connected with the hinge formed by folding line 56. As illustrated by FIG. 7, which shows an intermediate position, setting up the box results in the one corner portion 10e of the flap 10b settling above end flaps 17b and 13b, while end flap 11b settles like a lid over the whole end. Edge is drawn in, thereby uncovering a portion 10f on flap 13b. Flap 11b is glued against this portion so that sealing is obtained at edge 10c. If the contacting surfaces between the end flaps have a thermomelt coating, closure is done in a manner known per se by heat and pressure.

However, an extra strong and well-sealed closure can be provided by lifting up the lid forming flap llb so much that the glueing at 58 ruptures, and flap llb will be easily accessible for the application of a glue bead, whereafter flap 11b is immediately closed. This end closure will also be so tight that it satisfies normally current demands for powdery content in the box, without having to use a sealing lining in the box or a sealable bag which is introduced into the box to achieve complete tightness.

Both the end closures described above and on the drawings make it possible to supply flat folded boxes which can be set up at the place of use without expensive special machines, and which can be closed in a simple manner to obtain end closures having good sealability.

One can naturally use other bonding agents instead of glue at the places in the description where the use of glue is mentioned as an example.

If so required, the upper end of the box in the Figures can form a re-closable end closure. For example, if the opening flap 40 is glued fast to the area between folding lines 22 and 42 to the underlying end flap 11a in the closed state of the box, a free flap portion 40a remains outside the folding line 42, and forms a gripping flap. When this is pulled, the glueing is torn loose and the opening flap 40 can be folded back to open the box. When the box is closed afterwards, the opening flap 40 can be bent in towards end flap 11a and pushed into the space 60,60, FIG. 5, between flap 11a and the doublefolded end flaps 12a, 13a into a self-locking closing position.

What l claim is:

l. A carton box having a rear panel, a front panel and a pair of opposite side panels, said panels being at one end of the box extended with corresponding end flaps foldable along transverse end edge fold lines to enable closing and sealing the end of the box, the rear panel being at one of its edges extended with a side edge flap which is secured to the inside of the adjacent side panel, the end flap of the front panel being hingedly connected with the end flaps of the side panels along side edge fold lines, said end flaps being double-folded along 45 to fold lines so that they may be folded inwardly together with the end flap of the associated front panel, characterized in that the side edge flap also is extended with a side edge end flap, shorter than the other end flaps, and which along at least part of its one side edge is hingedly connected with the corresponding portion of the side edge of the end flap of the rear flap, for forming a side edge hinge; that the rear panel end flap is connected by means of a corresponding and equally located side edge hinge at its opposite side edge with a corresponding portion of the side edge of the adjacent side panel end flap; that a slit is provided in the rear panel end flap, defining an opening flap having side edges which extend to the end edge fold line between the rear panel and its end flap; that two intermediate fold lines parallel with lastmentioned end edge fold line are aligned with each other on opposite sides of the opening flap, and extend between the outer ends of the side edge hinges to their respective inner end points at the slit, dividing that portion of the end flap which is located between the slit and the end edge of the end flap, into two side end areas joining onto the side edge hinges and a flap end portion, which is separated by an edge slit from the adjacent side panel end flap, and has an edge glueing flap, foldable along a fold line parallel with the end edge fold lines; that the flap end portion is folded into the box, and is secured with the edge glue flap to the inside of the rear panel in a position where its fold line substantially coincides with the end edge fold line of the opening flap; and that from each end of the fold line of the edge glue flap a 45 fold line extends to the inner end point for the respective intermediate fold line and defines a triangular side area, lying against the inner side of the adjacent side end area, the arrangement being such, that when folding down the front panel end flap together with associated side panel end flaps this will result in a portion of the end flap of the rear panel lying between the edge hinges being folded inwards to a position at right angles to the rear panel, to form a supporting flap which at its ends is double folded along said 45 fold lines and which, after folding down the opening flap over the end flap of the front panel, will serve as an abutment or support for that pressure which is exerted on the flaps of the box end when sealing the same.

2. A carton box according to claim 1, characterized in that the opening flap has a glue bead adjacent associated end edge folding line, to provide a hermetic closure of the end flap edges situated here by the use of glue.

3. A carton box according to claim 1, characterized in that the slit in the rear panel end flap has an intermediate portion turning into slantingly directed side portions at the ends, said side portions extending up to the side end hinges and exposing the opening flap from ad jacent end flaps.

4. A carton box according to claim 1, characterized in that the opening flap has a number of mutually separated folding lines parallel with adjacent end edge folding line, to facilitate bending the opening flap after the box has been opened by tearing up the opening flap seal against the end flap, so that the opening flap can be bent and pushed in between the downwardly folded front panel end flap and the underlying double folded side panel end flaps. 

1. A carton box having a rear panel, a front panel and a pair of opposite side panels, said panels being at one end of the box extended with corresponding end flaps foldable along transverse end edge fold lines to enable closing and sealing the end of the box, the rear panel being at one of its edges extended with a side edge flap which is secured to the inside of the adjacent side panel, the end flap of the front panel being hingedly connected with the end flaps of the side panels along side edge fold lines, said end flaps being double-folded along 45* to fold lines so that they may be folded inwardly together with the end flap of the associated front panel, characterized in that the side edge flap also is extended with a side edge end flap, shorter than the other end flaps, and which along at least part of its one side edge is hingedly connected with the corresponding portion of the sIde edge of the end flap of the rear flap, for forming a side edge hinge; that the rear panel end flap is connected by means of a corresponding and equally located side edge hinge at its opposite side edge with a corresponding portion of the side edge of the adjacent side panel end flap; that a slit is provided in the rear panel end flap, defining an opening flap having side edges which extend to the end edge fold line between the rear panel and its end flap; that two intermediate fold lines parallel with lastmentioned end edge fold line are aligned with each other on opposite sides of the opening flap, and extend between the outer ends of the side edge hinges to their respective inner end points at the slit, dividing that portion of the end flap which is located between the slit and the end edge of the end flap, into two side end areas joining onto the side edge hinges and a flap end portion, which is separated by an edge slit from the adjacent side panel end flap, and has an edge glueing flap, foldable along a fold line parallel with the end edge fold lines; that the flap end portion is folded into the box, and is secured with the edge glue flap to the inside of the rear panel in a position where its fold line substantially coincides with the end edge fold line of the opening flap; and that from each end of the fold line of the edge glue flap a 45* fold line extends to the inner end point for the respective intermediate fold line and defines a triangular side area, lying against the inner side of the adjacent side end area, the arrangement being such, that when folding down the front panel end flap together with associated side panel end flaps this will result in a portion of the end flap of the rear panel lying between the edge hinges being folded inwards to a position at right angles to the rear panel, to form a supporting flap which at its ends is double folded along said 45* fold lines and which, after folding down the opening flap over the end flap of the front panel, will serve as an abutment or support for that pressure which is exerted on the flaps of the box end when sealing the same.
 2. A carton box according to claim 1, characterized in that the opening flap has a glue bead adjacent associated end edge folding line, to provide a hermetic closure of the end flap edges situated here by the use of glue.
 3. A carton box according to claim 1, characterized in that the slit in the rear panel end flap has an intermediate portion turning into slantingly directed side portions at the ends, said side portions extending up to the side end hinges and exposing the opening flap from adjacent end flaps.
 4. A carton box according to claim 1, characterized in that the opening flap has a number of mutually separated folding lines parallel with adjacent end edge folding line, to facilitate bending the opening flap after the box has been opened by tearing up the opening flap seal against the end flap, so that the opening flap can be bent and pushed in between the downwardly folded front panel end flap and the underlying double folded side panel end flaps. 